title: Root canals in two-rooted maxillary second molars.
abstract: The aim of this study was to register the root canal number, root canal position, and root canal cross-section in human two-rooted, permanent maxillary second molars. One hundred and fifty-nine such teeth extracted in Denmark were cross-sectioned at the mid-root level and apically in accordance with precise guidelines. The observations were made in a stereomicroscope, corresponding to the above-mentioned section levels. At mid-root there were two canals present in 11% of the teeth examined; the canals were located mesially and distofacially, mesiofacially and distally, or facially and lingually. Three canals positioned mesiofacially, distofacially, and lingually were observed in 89% of the teeth. At the same level 62% of the canal cross-sections were noncircular, some being, for instance, C-shaped, whereas 38% of the cross-sections were circular. Apically, two canals were found, representing 19% of the teeth, with the canal position as at mid-root; 81% of the teeth were three-canaled with the same canal position as at mid-root. At the apical level 60% of the canal cross-sections were noncircular, whereas 40% of the cross-sections were circular.
authors.affiliation: Department of Dental Morphology, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark.
authors.forename: O
authors.initials: O
authors.lastname: Carlsen
authors.forename: V
authors.initials: V
authors.lastname: Alexandersen
mesh_terms: D019412:Anatomy, Cross-Sectional; D002965:Classification; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D006801:Humans; D008437:Maxilla; D008963:Molar / Q000033:anatomy & histology*; D019227:Tooth Apex / Q000033:anatomy & histology; D019237:Tooth Cervix / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology*